Layer-2 Redundancy Protocol Interconnection Device

Abstract

Interconnection devices and interconnect a network running a redundancy protocol and another network running a redundancy protocol. The interconnection devices controls the redundancy protocol of a lower level network via virtual ports and by a virtual link, to redundancy-connect the lower level network to a higher level network. When a communication route of the lower level network is changed, MAC address learning results of the higher level network are cleared to perform switching of communication routes at high speed.

1 . A device for interconnecting a higher level network using a redundancy protocol providing communication routes with redundancy and a lower level network using a redundancy protocol same as or different from the redundancy protocol of said higher level network, the device comprising:
 higher level ports for connection to said higher level network; and   lower level ports for connection to said lower level network,   
     wherein:
 the redundancy protocol of said higher level network operating at the device controls only said higher level ports, and the redundancy protocol of said lower level network operating at the device collects all said higher level ports to recognize all said higher level ports as a virtual port, and controls said virtual port and said lower level ports; and 
 the device and another device interconnecting said higher level network and said lower level network are connected via said virtual port by a virtual link using a route of said higher level network, and the redundancy protocol of said lower level network is operated via said virtual port and said virtual link to make the redundancy protocol of said higher level network establish the connection of said virtual link and to make said lower level network be redundancy-connected to said higher level network. 
 
   
   
       2 . The device according to  claim 1 , wherein a control packet to be transmitted to said virtual port by the redundancy protocol of said lower level network is transmitted to said higher level ports in accordance with a communicable/incommunicable state of said higher level ports under control of the redundancy protocol of said higher level network, and the redundancy protocol of said lower level network receives said control packet from said virtual port in accordance with the communicable/incommunicable state of said higher level ports under control of the redundancy protocol of said higher level network. 
   
   
       3 . The device according to  claim 1 , wherein a state of said virtual port possessed by the redundancy protocol of said lower level network is always set to an up-state, and the redundancy protocol of said lower level network controls said virtual port as a highest priority port, in selecting a communication route. 
   
   
       4 . The device according to  claim 2 , wherein said control packet of the redundancy protocol of said lower level network received from said virtual port is relayed to a higher level port other than the higher port received said control packet in accordance with the communicable/incommunicable state of said higher level port under control of the redundancy protocol of said higher level network. 
   
   
       5 . The device according to  claim 4 , wherein whether said control packet of the redundancy protocol of said lower level network received from said virtual port is relayed or not can be selected. 
   
   
       6 . The device according to  claim 1 , wherein:
 said higher level network and said lower level network are interconnected by the device and a plurality of other devices; and   the device is connected to said plurality of other devices via a plurality of virtual ports by a plurality of virtual links using routes of said higher level network, in one-to-one correspondence.   
   
   
       7 . The device according to  claim 2 , wherein the redundancy protocol of said lower level network transmits said control packet to said virtual port, and in judging said control packet received from said higher level port, judges the packet as said control packet received from said virtual port if the device receives a packet coincident with said control packet of the lower network by said redundancy protocol. 
   
   
       8 . The device according to  claim 2 , further comprising a virtual LAN (VLAN) dedicated to said control packet of said lower level network by said redundancy protocol, wherein when said control packet is to be transmitted to said higher level port via said virtual port, said redundancy protocol of said lower level network transmits said control packet to said dedicated VLAN, and in judging a packet received from said higher level port, judges the packet as a packet received from said virtual port if said packet is received from said dedicated VLAN. 
   
   
       9 . The device according to  claim 2 , wherein in transmitting said control packet, said redundancy protocol of said lower level network transmits said control packet by storing a lower level network number for identifying said lower level network in said control packet, and in judging a packet received from said higher level port, judges from said lower level network number stored in said control packet that the received packet is a packet received from said virtual port. 
   
   
       10 . The device according to  claim 2 , further comprising a dedicated VLAN in one-to-one correspondence with said virtual link, wherein in transmitting said control packet to said higher level port via said virtual port, said redundancy protocol of said lower level network transmits said control packet to said dedicated VLAN, and in judging a packet received from said higher level port, judges from said dedicated VLAN that said packet was received at which virtual port. 
   
   
       11 . The device according to  claim 2 , wherein in transmitting said control packet, said redundancy protocol of said lower level network transmits said control packet by storing a virtual link number for identifying said virtual link in said control packet, and in judging a packet received from said higher level port, judges from said virtual link number stored in said control packet that said packet was received at which virtual port. 
   
   
       12 . The device according to  claim 1 , wherein:
 said higher level network is also connected to other lower level networks different from said lower level network; and   the device further comprises a dedicated VLAN provided for said lower level network and for each of said other lower level networks, in transmitting said control packet to said higher level port via said virtual port, said redundancy protocol of said lower level network transmits said control packet to said dedicated VLAN of said lower level network belonging to the device, and in judging a packet received from said higher level port, judges that said packet is a packet received from said virtual port if said packet is received from said dedicated VLAN of said lower level network belonging to the device, whereas if said packet is received from said dedicated VLAN different from said dedicated VLAN belonging to the device, does not receive but relays said packet.   
   
   
       13 . The device according to  claim 1 , wherein:
 said higher level network is also connected to other lower level networks different from said lower level network; and   in transmitting said control packet, said redundancy protocol of said lower network transmits said control packet by storing a lower level network number for identifying each of said other lower level networks in said control packet, and in judging a packet received from said higher level port, judges that said packet is a packet received from said virtual port if said lower level network number stored in said control packet is said lower level network number of said lower level network belonging to the device, whereas if said lower level network number is said lower level network number different from said lower level network number of said lower level network different from said lower level network belonging to the device, does not receive but relays said packet.   
   
   
       14 . The device according to  claim 1 , wherein when a change in a communication route occurs by said redundancy protocol of said lower level network, a MAC address learning clear packet is transmitted from said higher level port, and when said MAC address learning clear packet is received from said higher level port, MAC address learning results at said higher level ports are cleared. 
   
   
       15 . The device according to  claim 14 , wherein said MAC address learning clear packet is transmitted to said higher level port in accordance with a communicable/incommunicable state of said higher level port to be controlled by said redundancy protocol of said higher level network, and received in accordance with a communicable/incommunicable state of said higher level port to be controlled by said redundancy protocol of said higher level network. 
   
   
       16 . The device according to  claim 2 , wherein a health check packet is transmitted/received at a periodical interval to/from said virtual link via said higher level port to confirm communication arrivability of said virtual link, a state of said virtual port is set to an up-state while said communication arrivability is confirmed, and if said health check packet is not received in a predetermined time, the state of said virtual port is changed to a down-state and a communication route of said lower level network is changed by said redundancy protocol. 
   
   
       17 . The device according to  claim 16 , wherein if said health check packet is received after the state of said virtual port is changed to the down-state, the state of said virtual port is changed to the up-state and a communication route of said lower level network is changed by said redundancy protocol. 
   
   
       18 . The device according to  claim 16 , wherein when said higher level network is recovered by said redundancy protocol of said higher level network after the state of said virtual port is changed to the down-state, said redundancy protocol of said higher level network recovers communications of only said control packet, said health check packet and said MAC address clear packet respectively be said redundancy protocol of said lower level network via said virtual link, after the recovery, the state of said virtual port is changed to the up-state, a communication route is changed by the redundancy protocol of said lower level network, and thereafter data communications are recovered by said redundancy protocol of said higher level network.